What possible motive?

What possible motive can there be for an act like this other than utter fucking lunacy? Sometimes I think even trying to understand is flirting with madness.

BAGHDAD (AP) — A female suicide bomber struck a tent filled with women and children resting during a pilgrimage south of Baghdad on Friday, killing 40 people and wounding about 80 in the deadliest of three straight days of attacks against Shiite worshippers.

The rest of the story is at Associated Press, but honestly, I can’t think of a reason why you’d want to read the rest.